Selenium Involvement in the Oxidation by Rat Liver Tissue of Certain Tricarboxylic Acid Cycle Intermediates

Publisher Website
Google Scholar
Abstract
In 3 separate experiments, rats were fed for 5 or 11 weeks a basal diet deficient in selenium and vitamin E, or similar diets supplemented with either or both of these factors and ethoxyquin. On termination of the feeding period the rats were killed, their livers removed and subjected to studies in vitro. Results showed that selenium was associated with the oxidation of pyruvate by the liver preparations, but not with oxidation of succinate. When the feeding period was extended from 5 to 11 weeks, it was necessary to add vitamin E to the basal diet in order for the effect of selenium on pyruvate metabolism to be manifested. The co-involvement of selenium and vitamin E was evident even in the presence of presumably adequate amounts of the synthetic antioxidant, ethoxyquin. The data suggest a direct involvement for selenium in the oxidative processes of the tricarboxylic acid cycle, and further suggest a metabolic role for vitamin E over and above that of a lipid antioxidant.